Hi, just read this thread, now locked by moderators.
//www.diynot.com/forums/viewtopic.php?t=137661
Probably teaching you how to suck eggs... but if you are decommissioning a back boiler, and leaving bits of it in the chimney behind something that gets hot, make sure its all vented with holes drilled in the jacket for example, and the pipework not just sealed up, or it may well go bang at some point.
//www.diynot.com/forums/viewtopic.php?t=137661
Probably teaching you how to suck eggs... but if you are decommissioning a back boiler, and leaving bits of it in the chimney behind something that gets hot, make sure its all vented with holes drilled in the jacket for example, and the pipework not just sealed up, or it may well go bang at some point.